IDENTIFICATION OF A STRUCTURAL CHROMOSOMA L REARRANGEMENT IN THE KARYOTYPE OF A ROOT VOLE FROM CHERNOBYL BY BANDING TECHNIQUES

Karyological studies of rodents within a 30-km radius of the Chernobyl ' nuclear power plant revealed one female root vole (Microtus oeconomu s) with an abnormal karyotype. The use of C, G, and AgNOR banding meth ods allowed us to determine that morphological changes in two nonhomol ogous autosomes, which were accompanied by rearrangements in distribut ion of G bands, heterochromatin, and NOR, are the result of a reciproc al translocation. Chromosomal aberrations were probably inherited or a ppeared in embryogenesis, since none of the analyzed cells of the stud ied vole had a normal karyotype. It is important to note that this rea rrangement was detected five years after the meltdown. Both breaks and reunions of the chromosomes that participate in this rearrangement ar e probably located in regions that are not important for functioning o f these chromosomes. Thus, it can be supposed that the detected rearra ngement did not influence the viability of the vole. This karyotype wa s compared to a standard karyotype of a root vole from another area of the species range. The heteromorphism of the first pair of chromosome s in both voles, which was detected for the first time, is probably no rmal for the karyotype of M. oeconomus, and is not linked with any rad iation-induced intrachromosomal aberrations.